WO2004105109A1

WO2004105109A1 - Dicing device

Info

Publication number: WO2004105109A1
Application number: PCT/JP2004/006977
Authority: WO
Inventors: Masayuki Azuma; Yasuyuki Sakaya
Original assignee: Tokyo Seimitsu Co., Ltd.
Priority date: 2003-05-22
Filing date: 2004-05-17
Publication date: 2004-12-02
Also published as: TW200501252A; KR20060055457A; US20060243710A1; DE112004000766T5; JP4640173B2; JPWO2004105109A1

Abstract

A dicing device is provided with a dicing section, an expand section for enlarging the spacing between individual chips obtained by stretching and dicing a dicing sheet, and an inspection means for confirming the dicing state and expand state of a wafer. This makes it possible to perform the processing ranging from the dicing start to the end of expand in a short time, and to dice the next wafer while confirming the state of the wafer already diced.

Description

Specification Document Dicing Equipment

The present invention relates to a dicing apparatus for dividing a wafer such as a semiconductor device or an electronic component into individual chips, and more particularly to a dicing apparatus for dividing a wafer attached to a dicing sheet into individual chips. is there. Background art

Conventionally, to divide a wafer with semiconductor devices, electronic parts, etc. formed on the surface into individual chips, a dicing device that cuts the wafer by putting a grinding groove in the wafer with a grinding stone called a dicing blade. Was used. The dicing blade is an electrode made of fine diamond abrasive grains electrodeposited with Ni, and an extremely thin one having a thickness of about 30 m is used. The dicing blade was rotated at a high speed of 30, 00 to 60, 0 0 0 r p m to cut into a piece, and the piece was cut completely (full cut) or incompletely cut (half cut or semi full cut). Full cut is a method of cutting the wafer pasted on the dicing sheet until it has a cut of about 10 / xm in the dicing sheet, and half cut by cutting it to about half the thickness. Semi-flutter is a method of forming a grinding groove leaving a thickness of about 10 m in Wauha.

However, in the case of grinding with a dicing blade, because the 8A-8 is a highly brittle material, it becomes brittle mode processing, chipping occurs on the front and back surfaces of the chip, and the chip performance of the divided chips is It was a factor to reduce it. In particular, chipping on the back side was a troublesome problem as cracks gradually progressed to the inside.

As a means to solve this chipping problem in the dicing process, instead of cutting with a conventional die-sinter blade, a laser beam whose focusing point is aligned inside a wafer is used. A laser processing apparatus has been proposed that forms a modified region by multiphoton absorption inside the waha, and divides the waha into individual chips with the modified region as a base (for example, 2002-192367, JP-A-2002-192368, JP-A-2002-192369, JP-A-2002-192370, JP-A 2002-192371, JP-A 2002-205180).

After this dicing process, the wafer is transferred to a die bonding apparatus, and an expanding process is performed to extend the dicing sheet to expand the distance between the individual chips, and then the individual chips are picked up and die-bonded onto the substrate. Will be

However, a conventional dicing apparatus using a dicing blade is one in which a dividing groove is formed on a wafer with a very thin dicing blade having a thickness of about 3 O m, and is proposed in the above-mentioned patent publication In the laser processing equipment, it is divided into chips by cleaving by cleavage action along the crystal plane of WAE, based on the modified region formed inside the WAE, and in both cases, the distance between chips is extremely narrow. It is a thing.

Therefore, when the diced wafer is transported from the dicing machine or the laser processing machine to the die bonding machine, the WAE attached to the dicing sheet gathers, and the edges of the chips come in contact with each other, and the edge portion There is a problem that the chibbing occurs. In addition, after the dicing process, the wafer was transferred to the die bonding apparatus and the expanding process was performed, so the process from dicing to expanding took a long time. Furthermore, in the die bonding machine, the dicing sheet is expanded to expand the distance between the chips, and when picking up individual chips using the modified area as a base point, chip pick-up problems occur. In order to avoid such problems, chip pick-up is performed without checking whether the chip spacing has been adequately extended or not, and whether there is a defective chip with chipping at the chip edge.

For this reason, if the dicing sheet is not properly divided or expanded, there is a problem that the chip may be damaged due to die bonding to the base material up to the defective chip or chip pick-up failure. The

Also, in the prior art, after dicing and expanding, the state of the eight is There is a problem that it takes a lot of time when processing a large number of waehs because it is confirmed and repeated for each waeh.

The present invention has been made in view of such circumstances, and provides a dicing apparatus capable of performing processing from the start of dicing to the end of expansion in a short time and preventing the generation of defective chips. To aim. Disclosure of the invention

In order to achieve the above object, the present invention is a dicing apparatus for dicing a wafer attached to a dicing sheet, the dicing unit for dicing the wafer and dividing it into individual chips, and the die sintering sheet There is provided a dicing apparatus comprising: an expanding section which expands to expand a distance between the individual chips; and an inspection means for confirming the state of the wafer 8.

In the present invention, the inspection means may be provided in the expander. Further, the inspection means may confirm the expansion state of the interval between the chips.

In the present invention, the dicing section may be a laser dicing section that dices the wafer by causing a laser beam to be incident from the surface of the wafer and forming a modified region in the inside of the wafer. Good.

Furthermore, in the present invention, the inspection means may confirm the formation state of the modified region formed in the interior of the wafer 8 by the laser dicing part. Further, in the present invention, the inspection means confirms the formation state of the modified region formed in the interior of the wafer by the laser dicing part, and confirms the expansion state of the distance between the chips. May be

In the dicing apparatus according to the present invention, since the expanding part is provided, the transport distance of the diced fab eight is small, and it is possible to prevent chipping at the edge of the chip during transport. . In addition, the expanding section enables expansion immediately after dicing, and processing from the start of dicing to the end of expansion Can be done in a short time.

Further, in the dicing apparatus according to the present invention, since the inspection means for confirming the state of the wafer is provided, the expanded state can be confirmed after the expansion, and furthermore, the laser is formed inside the wafer 8 by the laser. The formation state of the modified region can be confirmed before expansion. As a result, defective chips are die-bonded, and chip pick-up defects do not damage the chips.

Further, according to the present invention, since the inspection means for confirming the state of the wafer is provided, the next dicing of the wafer 8 should be performed while confirming the dicing state or expanding state of the already diced eight. Can. That is, the dicing operation of the wafer can be performed in parallel with the confirmation operation of the dicing state or the expanding state, and a large number of wafers can be processed in a short time. Brief description of the drawings

FIG. 1 is a schematic view of a dicing apparatus according to the present invention;

FIG. 2 is a conceptual diagram for explaining a laser dicing unit;

FIG. 3 is a conceptual diagram for explaining an expanding part;

Figure 4 is a perspective view showing a frame mounted on a frame;

Fig. 5 (a) and Fig. 5 (b) are conceptual diagrams for explaining the reformed region formed in the interior of the WA. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the dicing apparatus according to the present invention will be described in detail with reference to the attached drawings. In the drawings, the same members are denoted by the same numbers or symbols. FIG. 1 is a plan view showing a schematic configuration of a dicing apparatus according to the present invention. In the dicing apparatus 10, as shown in FIG. 4, a state in which the adhesive is attached to a die sintering sheet T having an adhesive material on one side and the frame is integrated with the frame F through the die sintering sheet T. It is carried in and transported in the dicing machine 10. Dicing device 10, as shown in FIG. 1, is a cassette storage unit 90, an elevation plate 91, a laser dicing unit 40 as a dicing unit, an expanding unit 60, a wafer W not shown. It comprises means, a control unit 50 described later, and a television monitor 36 etc. described later.

The cassette storage unit 90 stores a cassette in which a large number of cassettes W integrated with the frame F via the dicing sheet T are stored. Elevation plate 91 has a frame clamper (not shown) which is moved up and down and moved back and forth, and clamps frame F with the frame clamper to take out the wafer W from the cassette or diced wafer W Put the container in the basket.

The laser dicing unit 40 injects laser light from the surface of the wafer W, and dices the wafer W into individual chips by forming a modified region inside the wafer W. In the expanding section 60, the dicing sheet T to which the diced wafer W is attached is expanded to expand the distance between the individual chips.

The transport means transports the wafer W to each part of the dicing apparatus 10. The control unit 50 is provided with a CPU, a memory, an input / output circuit unit, various drive circuit units and the like, and each is connected by a bus line to control the operation of each unit of the dicing apparatus 10. A program setting screen and various observation screens are displayed on the TV monitor 36.

An X guide rail 17 disposed in the X direction in FIG. 1 is mounted on the main body base 16. Also, a gate-shaped Y guide rail 18 is attached, which extends in the Y direction in FIG. 1 across the X guide rail 17 above the X guide rail 17.

The X guide rail 1 guides the XZ 0 table 1 1 of the laser dicing section 40, and the Θ Θ table 1 1 is moved in the X direction by drive means (not shown). As this driving means, known driving means such as a linear motor are used.

The Y guide rail 18 guides the Y table 19 to which the laser 1 optical unit 20 of the laser dicing unit 40 and the observation optical unit 30 described later are attached, and also the expansion unit 60 Guide Y movement table 81, Y table 1 9 and Y movement table 8 1 are accurately indexed in Y direction by drive means such as linear motor not shown respectively Will be sent.

An X moving table 81 moving in the X direction is incorporated in the Y moving table 81 in the expanding section 60, an inspection means 70 is attached to the X moving table 81, and the inspection means 70 is in the X direction It is moved and indexed accurately in the Y direction.

FIG. 2 is a conceptual block diagram showing the details of the laser dicing unit 40. As shown in FIG. The laser dicing unit 40 comprises an XZ 0 table 11, a laser optical unit 20, an observation optical unit 30, and the like.

XZ 0 table 1 1 is guided by X guide rail 1 7 and moved in the X direction X table 1 2 mounted on X table 1 2 and driven in the Z direction and 0 direction in FIG. 2 Table 1 The suction stage 13 for holding the wafer W through the dicing sheet T and the pedestal 14 for holding the frame F are attached to the table 15. By this XZ 0 table 1 1, the wafer W is precisely moved in the XZ 0 direction in FIG.

The laser optical unit 20 is attached to a Y-table 19 so that it is precisely index-fed in the Y direction. The laser oscillator 21, the collimating lens 22, the half mirror 2 3, the condensing lens 2 It is composed of 4 mag.

The observation optical unit 30 is composed of an observation light source 31, a collimator lens 32, a half mirror 33, a condenser lens 34, a CCD camera 35 as an observation means, a television monitor 36 and the like.

In the laser 1 optical unit 20, the laser 1 light oscillated from the laser oscillator 21 is condensed inside the wafer W through an optical system such as a collimating lens 22, a half mirror 23 and a condensing lens 24. Ru. Here, a laser beam having permeability to the dicing tape is used under the condition that the peak power density at the focal point is 1 × 10 ⁸ (W / cm ² ) or more and the pulse width is 1 s or less. . The Z direction position of the focusing point is adjusted by the Z direction fine movement of the XZ 0 table 1 1.

In the observation optical unit 30, the illumination light emitted from the observation light source 31 passes through the optical system such as the collimating lens 32, the half mirror 33 and the condensing lens 24 and so on. Irradiate. The reflected light from the surface of the W W is incident on the CCD camera 35 as an observation means via the condensing lens 24, half mirrors 23 and 33, and the condensing lens 34, and the surface image of the W W is captured Be done.

This imaging data is input to the image processing unit 38, used as an alignment of the W-ha W, and taken out on the television monitor 36 via the control unit 50.

FIG. 3 is a conceptual block diagram showing details of the expanding unit 60. As shown in FIG. The expanding section 60 is for expanding the distance between the individual chips C of the wafer W diced while being affixed to the dicing sheet T, and the dicing sheet T is directed outward from the central portion. Expand by stretching.

Expanding part 60 is supported vertically movably by sliding on base 61 fixed to body base 16, receiving ring 62 attached to base 61 and outer periphery of receiving ring 62. The press ring 63 is configured to press the frame F to which the dicing sheet T is attached downward, and a driving unit such as an air cylinder (not shown) that vertically moves the press ring 63.

The expanding section 60 is provided with an inspection means 70 for confirming the state of the light W. In the inspection means 70, the illumination light emitted from the light source 71 passes through the optical system such as the collimator lens 72, the half mirror 73, the condensing lens 74 and the like to illuminate the wafer W. The reflected light of the irradiated light passes through the condensing lens 74, the half mirror 73, and the condensing lens 75, and enters the CCD camera 76 as an observation means, and an observation image is captured. The imaging data is input to the image processing unit 38, and the state of the camera is confirmed, and is output to the television monitor 36 via the control unit 50.

The inspection means 70 is moved in the X direction and the Y direction above the wafer W by an X moving table 8 2 and a Y moving table 81 disposed above the expanding unit 60. Infrared light is used for the light source 71. If the formation state of the modified area formed inside the Wah W by laser light is confirmed before expansion, the inside of the Wah W is focused at high magnification to focus the image. take in. Also, when checking the expanded state after expansion, focus on the surface of the wafer at low magnification and capture an image. These pictures The image data is processed by the image processing unit 38 and sent to the control unit 50 so that the state of the image can be analyzed.

Next, the operation of the dicing apparatus 10 configured as described above will be described. The wafer W mounted on the ring-shaped frame F through the dicing sheet T is pulled out of the cassette stored in the cassette storage unit by the clamper provided on the elevator 91, and the laser dicing is performed by the transfer means. Part 40 is transported onto the XZ 0 table 1 1 and held by suction on the suction stage 13.

The wafer W held by suction on the suction stage 13 is first imaged with a circuit pattern formed on the surface by the CCD camera 35, and is aligned by the image processing unit 38 and the alignment means provided in the control unit 50. Alignment of the direction and positioning in the XY direction are done. When alignment is completed, X Z 0 table 1 1 moves in the X direction and laser light is incident along Dai Shinda Street of W W W. Since the focusing point of the laser light incident from the surface of the W W is set at the inside in the thickness direction of the W W, the laser light transmitted through the W W surface is the light collected inside the W A The energy is concentrated at the point, and reformed regions such as a crack region, a melting region, a refractive index change region, etc. are formed in the vicinity of the light condensing point inside the light W by multiphoton absorption. As a result, the balance of the intermolecular force is broken, and it becomes broken by cutting naturally or by applying a slight external force. FIG. 5 is a conceptual diagram for explaining a reforming region formed in the vicinity of a light condensing point in the interior of the wafer. Fig. 5 (a) shows a state in which the laser light L incident on the inside of the wah W forms a modified region P at the focusing point, and Fig. 5 (b) shows the lower part of the pulsed laser light L. At this time, W 八 8 W is moved in the horizontal direction, and discontinuous reforming areas P are formed side by side. In this state, Wahha W is cleaved from the reforming region P as a starting point by applying a force that cleaves naturally from the reforming region P as a starting point or a slight external force. In this case, the wafer W is easily divided into chips without chipping on the front and back surfaces.

When the formation of the modified region P of one line is completed, the Y table to which the laser optical unit 20 is attached is sent in the 1-index Y direction, and the laser light is incident along the next diameter. Modified area P is formed inside ゥ 18 When reformed area formation is performed for all dicing streets in one direction, Z 0 table 15 rotates 90 °, and all reformed area formation is also performed for the dicing dust which intersects with the previous Dai Shinda street. Is done.

The wafer W in which the laser dicing that forms the reformed area P inside is performed for all the dicing streets is conveyed by the conveying means to the expanding section 60 and the receiving ring provided in the expanding section 60 6 Set on 2nd.

Here, the inspection means 70 confirms the state of formation of the reformed region inside. The confirmation is performed by scanning the infrared light from the light source 71 with the X moving table 82 and the Y moving table 81 and capturing an image inside the window. The reformed area formation state can be confirmed by the screen displayed on the television monitor 36, and the quality of the reformed area formation state judgment unit (not shown) provided in the control unit 50 is automatically judged as good or bad. Also, the judgment result is fed back to the irradiation condition of laser light L.

Next, when the formation of the reformed area is confirmed, the press ring 63 is lowered to push down the frame F and expand the dicing sheet T. At this time, since the outer peripheral edge portion 6 2 A of the upper surface of the receiving ring 62 is chamfered in an arc shape, the cylinder D is smoothly expanded and the distance between the individual chips C is expanded.

Next, the surface of the plurality of chips C is imaged by the inspection means 70, and the expanded state is inspected. This inspection is performed by scanning the inspection means 70 across the front surface of the scanning unit 70 by the X movement table 82 and the Y movement table 81, and the imaged image is processed by the image processing unit 38 and the image data is Sent to control unit 50.

The control unit 50 displays the expanded state on the television monitor 36, and automatically determines whether or not the chip interval is expanded by a predetermined amount. This judgment result is also fed back to control the amount of descent of the press ring 63. In addition, the size of the chipbing on the periphery of chip C is also checked.

Next, the slack portion of the expanded dicing sheet T is processed, and the individual chips C attached to the dicing sheet T are carried out together with the frame F from the spanned portion 60 by the transport means. Then by Elebe 9 1 1 the original position of the cassette It is put back into place.

Thus, the wafer W stored in the cassette is sequentially diced by the laser dicing section 40, and then the formation state of the modified region formed inside is confirmed by the expand section 60, and the expanded Further, the expanded state is confirmed. For this reason, the distance between the chips C on the dicing sheet T is stably expanded by a predetermined amount. In addition, when one piece of wafer W is completed for laser dicing and transferred from the laser dicing part 40. to the expanding part 60, the next wafer W is carried into the laser dicing part 40 again. Therefore, the confirmation of the formation of the modified region and the confirmation of the expand state are performed when the next wafer is being laser-diced. Therefore, the condition of the wafer W is confirmed without reducing the processing speed of the dicing apparatus 10 can do. In the above-described embodiment, the laser dicing unit 40 is used as the dicing unit, in which the modified region is formed inside the wafer W by using a laser beam, but the present invention is not limited to this. It may be a dicing section using a dicing blade. In this case, the inspection means 70 does not need to confirm the state of formation of the modified region, and hence the light source 71 does not need to be infrared light, and may be a white light source. Industrial applicability

As described above, in the dicing apparatus according to the present invention, the expanding section can perform expansion immediately after dicing. Therefore, processing from the start of dicing to the end of expansion can be performed in a short time. Also, the problem that the edges of the individual diced chips come into contact with each other during the transportation of the diced wafer 8 and the chipping occurs at the edges is solved.

Further, according to the present invention, the expanded state can be confirmed after the expansion. Therefore, it is possible to check whether or not the chip interval is appropriately expanded, and whether there is a defective chip with a chip at the chip edge. Furthermore, before the expansion is performed, the formation state of the modified region formed in the interior of the wye by the laser can be confirmed. Therefore, the formation condition of the modified region is a feed bar under the laser irradiation condition It is possible to improve the resolution by forming a reformed region in an appropriate state. As a result, there is no possibility of die bonding of a defective chip or damage to the chip due to chip pickup failure, and generation of a defective chip can be prevented.

Further, according to the present invention, since the inspection means for confirming the state of the wye 8 is provided in the expanding section, while checking the dicing state or the expand state of the already diced wye 8 next Dicing can be performed. In other words, it is possible to concurrently perform the dicing operation of WAE 8 and the confirmation operation of dicing status or expanding status, and the processing speed of the dicing apparatus can be improved.

Claims

The scope of the claims

1. A dicing apparatus for dicing a wafer attached to a dicing sheet, comprising:-a dicing unit for dicing the wafer and dividing it into individual chips; and extending the dicing sheet to separate the individual chips. An expanse that extends the interval between

A verification means for confirming the condition of the w18;

A dicing apparatus comprising

2. The dicing apparatus according to claim 1, wherein the inspection unit is provided in the expanding unit, and confirms an expanded state of a space between the individual chips.

3. The dicing section is a laser single dicing section for dicing the wafer by entering a laser beam from the surface of the wafer and forming a modified region in the inside of the wafer. The dicing apparatus according to claim 1.

4. The dicing unit is a laser dicing unit for dicing the wafer by irradiating a laser beam from the surface of the wafer and forming a modified region in the inside of the wafer, and the inspection A means is provided in the said expansion part and confirms the expansion state of the space | interval of each said chip | tip? The dicing apparatus according to claim 1, wherein:

5. The dicing unit is a laser dicing unit for dicing the wafer by irradiating a laser beam from the surface of the wafer and forming a modified region in the inside of the wafer, The dicing apparatus according to claim 1, wherein the inspection unit confirms the formation state of the modified region formed in the inside of the wafer 8 by the laser dicing unit.

6. The dicing section is a laser dicing section for dicing the wafer by irradiating a laser beam from the surface of the wafer and forming a modified region inside the wafer. The detection means is provided in the expanding section; The method according to claim 1, characterized in that the expansion state of the spacing between the chips is confirmed, and the formation state of the modified region formed in the interior of the wafer 8 is confirmed by the laser dicing section. Dicing equipment.